**Leaf-footed Bugs** (family Coreidae, genus *Leptoglossus* and related) are large, distinctively-shaped true bugs that are major agricultural and garden pests. They are named for the distinctive, flattened, leaf-like enlargements on the lower segments of their hind legs. Both the adult and the nymph feed by piercing plant tissue (especially developing fruit, nuts, and seed pods) and sucking out the contents. They are severe pests of tomatoes, citrus, cotton, and many seed crops, causing damage that leads to deformation, discoloration, and loss of market value.
Taxonomy and Classification
Leaf-footed Bugs belong to the order Hemiptera (true bugs). They undergo incomplete metamorphosis. They are closely related to squash bugs and stink bugs. When disturbed, they often emit a strong, unpleasant odor. The adults are highly mobile and often aggregate in large numbers on fruiting plants.
Physical Description
Adult Leaf-footed Bugs are large, slender insects, 3/4 to 1 inch long.
- **Appearance (Key ID):** Dark brown or black body. The most defining feature is the **flared, leaf-like segment** (tibia) on the hind legs. Often, a white or yellow band is visible across the middle of the back.
- **Nymphs:** Distinctively bright orange or red when young, maturing to a dark brown with black spines, and often found clustered together.
- **Damage Sign (Key ID):** Puncture marks (feeding stylet holes) visible on the surface of fruit or nuts. The tissue beneath the puncture turns white, corky, or mushy, and the fruit or vegetable is often deformed.
- **Nuisance:** Emits a foul odor when handled or crushed.
Distribution and Habitat
Leaf-footed Bugs are found primarily in the warmer climates of North, Central, and South America. Their habitat is weedy fields, gardens, orchards, and vineyards, where they feed on the reproductive parts of plants.
Behavior and Conflict
The conflict is direct damage to high-value fruit and nut crops.
- **Feeding Damage:** Their piercing-sucking mouthparts penetrate deeply, causing internal damage that makes the fruit or nut unsalable. They are especially damaging to developing tomatoes, pecans, and pomegranates.
- **Aggregation:** They often cluster together, allowing them to inflict heavy, localized damage quickly.
- **Odor:** The defensive odor is a minor nuisance when they are disturbed.
Management and Prevention
Control is integrated pest management (IPM), with a focus on sanitation and physical removal.
- **Weed Control (Key):** Eliminate weeds and vines near the garden, as these serve as alternate food sources and overwintering sites.
- Remove and destroy all crop debris at the end of the season.
- **Hand-Picking:** Due to their size, they can be manually picked off plants and dropped into a container of soapy water to drown.
- Use a small vacuum to remove nymphs and adults from plants in the morning when they are sluggish.
- Apply insecticides when nymphs are small and before they mature into highly mobile adults. Thorough coverage is essential, as they are relatively tough insects.
Conservation and Research
Leaf-footed Bugs are managed as high-priority agricultural and garden pests. Research focuses on identifying natural enemies (such as parasitic flies that target the adults) and developing better trapping systems that utilize their aggregation pheromones.